flower/libc-extension.cc

   1 /*
   2   libc-extension.cc --  compensate for lacking libc functions.
   3
   4
   5   source file of the flowerlib
   6
   7   (c) 1997 Han-Wen Nienhuys <hanwen@stack.nl>
   8 */
   9 #include <stdarg.h>
  10 #include <string.h>
  11 #include <ctype.h>
  12 #include "libc-extension.hh"
  13
  14
  15 char*
  16 strnlwr (char* start_l ,int n)
  17 {
  18     char * p = start_l + n;
  19     while (--p >= start_l)
  20     {
  21         *p = tolower (*p);    /* a macro on some compilers */
  22     }
  23     return start_l;
  24 }
  25
  26 char*
  27 strnupr (char* start_l, int n)
  28 {
  29     char * p = start_l + n;
  30     while (--p >= start_l)
  31     {
  32         *p = toupper (*p);    /* a macro on some compilers */
  33     }
  34     return start_l;
  35 }
  36
  37 #if !HAVE_MEMMEM
  38
  39 /** locate a substring. #memmem# finds the first occurrence of
  40   #needle# in #haystack#
  41   */
  42
  43 char *
  44 memmem (Byte const * haystack, int haystack_len,
  45         Byte const *needle,int needle_len)
  46 {
  47     Byte const * end_haystack = haystack + haystack_len - needle_len;
  48     Byte const * end_needle = needle + needle_len ;
  49
  50     /* Ahhh ... Some minimal lowlevel stuff. This *is* nice; Varation
  51        is the spice of life */
  52     while (haystack < end_haystack)
  53     {
  54         Byte const *subneedle_l = needle;
  55         Byte const *subhaystack_l = haystack;
  56         while (subneedle_l < end_needle)
  57         {
  58             if (*subneedle_l++ != *subhaystack_l++)
  59                 goto next;      // yeah. I should be prosecuted.
  60         }
  61
  62         // completed the needle. Gotcha.
  63         return (char*) haystack;
  64     next:
  65         haystack++;
  66     }
  67     return 0;
  68 }
  69 #endif
  70
  71 Byte *
  72 memrchr (Byte const * p, int n, char c)
  73 {
  74     const    Byte * q = p+n;
  75     while (q > p)
  76     {
  77         if (*--q == c)
  78             return (Byte*)q;
  79     }
  80     return 0;
  81 }
  82
  83
  84 template<class T>
  85 inline void
  86 my_swap (T &t1, T &t2, T &tmp)
  87 {
  88     tmp = t1;
  89     t1 = t2;
  90     t2 = tmp;
  91 }
  92
  93 Byte*
  94 strrev (Byte* byte_l, int length_i)
  95 {
  96     Byte tmp_byte;
  97
  98     Byte* left_l = byte_l;
  99     Byte* right_l = byte_l + length_i;
 100
 101     while (right_l > left_l)
 102     {
 103         my_swap (*right_l-- , *left_l++ , tmp_byte);
 104     }
 105     return byte_l;
 106 }
 107
 108 #if ! HAVE_SNPRINTF
 109 int snprintf (char *str, size_t,
 110                char const *format, ...)
 111 {
 112     va_list ap;
 113     va_start (ap, format);
 114     int i = vsprintf (str, format, ap);
 115     va_end (ap);
 116     return i;
 117 }
 118 #endif